Propylene Polymerization and Deactivation Processes with Isoselective {Cp/Flu} Zirconocene Catalysts
Industrially relevant single-site precatalysts used to produce isotactic polypropylene (iPP) include <i>C</i><sub>2</sub>-symmetric {SBI} and <i>C</i><sub>1</sub>-symmetric {Cp/Flu} complexes of group 4 metals. While the latter can produce iPPs with a...
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MDPI AG
2021-08-01
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| author | Xavier Desert Thierry Roisnel Vincent Dorcet Katty Den Dauw Aurélien Vantomme Alexandre Welle Jean-François Carpentier Evgueni Kirillov |
| author_facet | Xavier Desert Thierry Roisnel Vincent Dorcet Katty Den Dauw Aurélien Vantomme Alexandre Welle Jean-François Carpentier Evgueni Kirillov |
| author_sort | Xavier Desert |
| collection | DOAJ |
| description | Industrially relevant single-site precatalysts used to produce isotactic polypropylene (iPP) include <i>C</i><sub>2</sub>-symmetric {SBI} and <i>C</i><sub>1</sub>-symmetric {Cp/Flu} complexes of group 4 metals. While the latter can produce iPPs with a higher degree of isotacticity, they also suffer from poor productivity compared to their {SBI} counterparts. Several causes for this trend have been suggested—2,1-Regioinsertions are frequently pointed out, as they are suspected to drive the catalyst into a dormant state. While this event does not seem to significantly impact the productivity of {SBI} systems, the influence of these regioerror is poorly documented for isoselective {Cp/Flu} precatalysts. To address this issue, new Ph<sub>2</sub>X(Cp)(Flu) (Ph<sub>2</sub>X = Ph<sub>2</sub>C, FluC, Ph<sub>2</sub>Si) proligands (<b>2a</b>–<b>k</b>) and some of the corresponding dichlorozirconocenes (<b>3a</b>–<b>h</b>,<b>k</b>) were synthesized. These new compounds were characterized and tested in homogeneous propylene polymerization at 60 °C and the amounts of regioerrors in the resulting polymers were examined by <sup>13</sup>C NMR spectroscopy. A possible correlation between poor productivity and a high number of regioerrors was investigated and is discussed. Furthermore, a C-H activation process in the bulky <i>n</i>Bu<sub>3</sub>C substituent upon activation of <b>4c</b> (the dimethylated analog of <b>3c</b>) by B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> has been evidenced by NMR; DFT calculations support this C-H activation as a deactivation mechanism. |
| first_indexed | 2024-03-10T08:56:19Z |
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| issn | 2073-4344 |
| language | English |
| last_indexed | 2024-03-10T08:56:19Z |
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| spelling | doaj.art-369fd2df64b441ca9e4c48e45d8d018e2023-11-22T07:07:17ZengMDPI AGCatalysts2073-43442021-08-0111895910.3390/catal11080959Propylene Polymerization and Deactivation Processes with Isoselective {Cp/Flu} Zirconocene CatalystsXavier Desert0Thierry Roisnel1Vincent Dorcet2Katty Den Dauw3Aurélien Vantomme4Alexandre Welle5Jean-François Carpentier6Evgueni Kirillov7Institut des Sciences Chimiques de Rennes (ISCR), Univ Rennes, CNRS, UMR 6226, F-35042 Rennes, FranceCentre de Diffraction X, ISCR (Institut des Sciences Chimiques de Rennes), Univ Rennes, CNRS, UMR 6226, F-35700 Rennes, FranceCentre de Diffraction X, ISCR (Institut des Sciences Chimiques de Rennes), Univ Rennes, CNRS, UMR 6226, F-35700 Rennes, FranceTotal Research & Technology Feluy, Zone Industrielle Feluy C, B-7181 Seneffe, BelgiumTotal Research & Technology Feluy, Zone Industrielle Feluy C, B-7181 Seneffe, BelgiumTotal Research & Technology Feluy, Zone Industrielle Feluy C, B-7181 Seneffe, BelgiumInstitut des Sciences Chimiques de Rennes (ISCR), Univ Rennes, CNRS, UMR 6226, F-35042 Rennes, FranceInstitut des Sciences Chimiques de Rennes (ISCR), Univ Rennes, CNRS, UMR 6226, F-35042 Rennes, FranceIndustrially relevant single-site precatalysts used to produce isotactic polypropylene (iPP) include <i>C</i><sub>2</sub>-symmetric {SBI} and <i>C</i><sub>1</sub>-symmetric {Cp/Flu} complexes of group 4 metals. While the latter can produce iPPs with a higher degree of isotacticity, they also suffer from poor productivity compared to their {SBI} counterparts. Several causes for this trend have been suggested—2,1-Regioinsertions are frequently pointed out, as they are suspected to drive the catalyst into a dormant state. While this event does not seem to significantly impact the productivity of {SBI} systems, the influence of these regioerror is poorly documented for isoselective {Cp/Flu} precatalysts. To address this issue, new Ph<sub>2</sub>X(Cp)(Flu) (Ph<sub>2</sub>X = Ph<sub>2</sub>C, FluC, Ph<sub>2</sub>Si) proligands (<b>2a</b>–<b>k</b>) and some of the corresponding dichlorozirconocenes (<b>3a</b>–<b>h</b>,<b>k</b>) were synthesized. These new compounds were characterized and tested in homogeneous propylene polymerization at 60 °C and the amounts of regioerrors in the resulting polymers were examined by <sup>13</sup>C NMR spectroscopy. A possible correlation between poor productivity and a high number of regioerrors was investigated and is discussed. Furthermore, a C-H activation process in the bulky <i>n</i>Bu<sub>3</sub>C substituent upon activation of <b>4c</b> (the dimethylated analog of <b>3c</b>) by B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> has been evidenced by NMR; DFT calculations support this C-H activation as a deactivation mechanism.https://www.mdpi.com/2073-4344/11/8/959zirconocenepolymerizationpolypropyleneregiocontrolstereocontroldeactivation |
| spellingShingle | Xavier Desert Thierry Roisnel Vincent Dorcet Katty Den Dauw Aurélien Vantomme Alexandre Welle Jean-François Carpentier Evgueni Kirillov Propylene Polymerization and Deactivation Processes with Isoselective {Cp/Flu} Zirconocene Catalysts Catalysts zirconocene polymerization polypropylene regiocontrol stereocontrol deactivation |
| title | Propylene Polymerization and Deactivation Processes with Isoselective {Cp/Flu} Zirconocene Catalysts |
| title_full | Propylene Polymerization and Deactivation Processes with Isoselective {Cp/Flu} Zirconocene Catalysts |
| title_fullStr | Propylene Polymerization and Deactivation Processes with Isoselective {Cp/Flu} Zirconocene Catalysts |
| title_full_unstemmed | Propylene Polymerization and Deactivation Processes with Isoselective {Cp/Flu} Zirconocene Catalysts |
| title_short | Propylene Polymerization and Deactivation Processes with Isoselective {Cp/Flu} Zirconocene Catalysts |
| title_sort | propylene polymerization and deactivation processes with isoselective cp flu zirconocene catalysts |
| topic | zirconocene polymerization polypropylene regiocontrol stereocontrol deactivation |
| url | https://www.mdpi.com/2073-4344/11/8/959 |
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